The invention is directed to compounds that are useful in treating inflammation and that contain piperazine or piperidine moieties coupled to the 5- or 6-position of indole, benzimidazole or benzotriazole. More particularly, the invention concerns novel ortho substituted indoles and N-substituted indoles as well as methods to treat heart and kidney conditions using these compounds and derivatives thereof.
A large number of chronic and acute conditions have been recognized to be associated with perturbation of the inflammatory response. A large number of cytokines participate in this response, including IL-1, IL-6, IL-8 and TNF. It appears that the activity of these cytokines in the regulation of inflammation rely at least in part on the activation of an enzyme on the cell signaling pathway, a member of the MAP kinase family generally known as p38 and alternatively known as CSBP and RK. This kinase is activated by dual phosphorylation after stimulation by physiochemical stress, treatment with lipopolysaccharides or with proinflammatory cytokines such as IL-1 and TNF. Therefore, inhibitors of the kinase activity of p38 are useful antiinflammatory agents.
PCT applications WO98/28292, WO98/06715, WO98/07425, and WO96/40143, all of which are incorporated herein by reference, describe the relationship of p38 kinase inhibitors with various disease states. As mentioned in these applications, inhibitors of p38 kinase are useful in treating a variety of diseases associated with chronic inflammation. These applications list rheumatoid arthritis, rheumatoid spondylitis, osteoarthritis, gouty arthritis and other arthritic conditions, sepsis, septic shock, endotoxic shock, Gram-negative sepsis, toxic shock syndrome, asthma, adult respiratory distress syndrome, stroke, reperfusion injury, CNS injuries such as neural trauma and ischemia, psoriasis, restenosis, cerebral malaria, chronic pulmonary inflammatory disease, silicosis, pulmonary sarcosis, bone resorption diseases such as osteoporosis, graft-versus-host reaction, Crohn""s Disease, ulcerative colitis including inflammatory bowel disease (IBD) and pyresis.
The above-referenced PCT applications disclose compounds which are p38 kinase inhibitors said to be useful in treating these disease states. These compounds are either imidazoles or are indoles substituted at the 3- or 4-position with a piperazine or piperidine ring linked through a carboxamide linkage. Additional compounds which are conjugates of piperazines with indoles are described as insecticides in WO97/26252, also incorporated herein by reference.
The invention is directed to compounds useful in treating inflammation generally, including specific conditions such as those described in the Background section above. Certain novel compounds have been found to inhibit p38 kinase, in particular, p38 kinase xcex1 and are thus useful in treating diseases mediated by this enzyme. The compounds of the invention are of the formula: 
preferably those of the formulas: 
and the pharmaceutically acceptable salts thereof,
wherein each Z1 and Z2 is independently CR4 or N;
where each R4 is independently H or is alkyl (1-6C) or aryl, each of said alkyl or aryl optionally including one or more heteroatoms selected from O, S and N and optionally substituted by one or more of halo, OR, SR, NR2, RCO, COOR, CONR2, OOCR, or NROCR where R is H or alkyl (1-6C), or by one or more CN or xe2x95x90O, or by one or more aliphatic or aromatic 5- or 6-membered rings optionally containing 1-2 heteroatoms; or
two R4 taken together form a bridge optionally containing a heteroatom;
R1 is 
xe2x80x83wherein
X1 is CO or an isostere thereof,
m is 0 or 1;
Y is optionally substituted alkyl, optionally substituted aryl, or optionally substituted arylalkyl or two Y taken together may form an alkylene (2-3C) bridge;
n is 0, 1 or 2;
Z3 is CH or N;
X2 is CH, CH2 or an isostere thereof; and
Ar consists of one or two phenyl moieties directly coupled to X2 optionally substituted by halo, nitro, alkyl (1-6C), alkenyl (1-6C), alkynyl (1-6C), CN or CF3, or by RCO, COOR, CONR2, NR2, OR, SR, OOCR or NROCR wherein R is H or alkyl (1-6C)
or by phenyl, itself optionally substituted by the foregoing substituents;
R2 is H, or is alkyl (1-6C) or aryl each of said alkyl or aryl optionally including one or more heteroatoms which are O, S or N, and optionally substituted by one or more of halo, OR, SR, NR2, RCO, COOR, CONR2, OOCR, or NROCR where R is H or alkyl (1-6C), or by one or more CN or xe2x95x90O, or by one or more aliphatic or aromatic 5- or 6-membered rings optionally containing 1-2 heteroatoms;
R3 is H, halo, NO2, alkyl (1-6C), alkenyl (1-6C), alkynyl (1-6C), CN, OR, SR, NR2, RCO, COOR, CONR2, OOCR, or NROCR where R is H or alkyl (1-6C).
Thus, in one aspect, the invention is directed to compounds of the formulas set forth above. In other aspects, the invention is directed to methods to produce these compounds, to pharmaceutical compositions containing them, and to methods of treating inflammation using these compounds. The invention is also directed to treating conditions associated with cardiac failure using the invention compounds and other compounds described herein.
The compounds of formulas 1-4 are useful in a variety of physiological contexts, as further described below. Preferred embodiments include those wherein both Z1 and Z2 are CH or where Z1 is CR4 and Z2 is CH; thus, among the preferred compounds of the invention are derivatives of indole. Especially preferred substituents at the 3-position are those coupled through carboxamide linkages. Thus, some preferred embodiments of R4 are of the formula RNHCOxe2x80x94 wherein R is alkyl or substituted alkyl.
In general, substituents on the nitrogen-containing portion of the indole, benzimidazole, or benztriazole nucleus are designed to enhance solubility. Thus, typically, the substituents R2 and R4 are polar or contain polar groups.
In other preferred embodiments, the substituents shown for the compounds of the invention are as set forth below.
In regard to R1:
X1 is CO or an isostere thereof. Thus, in addition to CO, X1 may be CH2, SO, SO2, or CHOH. CO is preferred.
Z3 is CH or N; Z3=CH is preferred.
Typically m is 1; however, in some compounds of the invention, m can be 0; thus, this substituent is a five-membered ring.
X2 is CH2 if Ar consists of a single phenyl moiety or CH if Ar consists of two phenyl moieties or may be an isostere thereof. Thus, for appropriate embodiments of Ar, X2 may be any of the alternatives set forth above for X1.
The phenyl moieties represented by Ar may optionally be substituted by substituents including alkyl (1-6C), halo, RCO, COOR, CONR2, OR, SR, NR2, OOCR, NROCR, NO2, CN, or CF3, wherein R is H or alkyl (1-6C). The phenyl moieties may also be substituted with an additional phenyl residue, preferably at the 4-position. The additional phenyl residue may itself be substituted with the substituents set forth above. The additional phenyl may be substituted in all five positions, but preferably less, preferably in 1-2 positions or not at all. Preferred substituents include alkyl (1-6C), OR, NR2 and halo, especially halo and OCH3. The substituents may occupy all five positions of the phenyl substituent, preferably 1-2 positions or the phenyl may be unsubstituted.
n may be 0, 1 or 2, and is preferably 0. However, when n is 1, Y is present and may be alkyl, arylalkyl or aryl, all of which may optionally be substituted by the substituents set forth above with regard to Ar. When n is 2, both Y groups together may constitute an alkylene bridge. A preferred bridge is an ethylene bridge. Preferred embodiments of Y when n is 1 include unsubstituted alkyl and unsubstituted arylalkyl.
With regard to R2:
R2 is preferably H, but may also be a suitable substituent. Such substituents are typically and preferably alkyl or substituted alkyl. The alkyl or substituted alkyl may optionally include one or more heteroatoms which can be O, N or S, preferably N and O. Permitted substitutions on the alkyl group are set forth above; preferred substituents include OR, where R is H or alkyl (1-6C) and xe2x95x90O. Also included among the preferred substituents on the alkyl group are cyclic moieties, such as piperazine, pyridine, piperidine, phenyl, and the like. Preferably, the alkyl embodiments of R2 contain 0, 1 or 2 substituents. Among preferred embodiments of R2 are included those of the formula xe2x80x94(CO)Oxe2x80x94Yxe2x80x2 wherein Yxe2x80x2 is, for example, xe2x80x94(CH2)nNR2, where n is an integer of 0-6 and R is as defined above; or Yxe2x80x2 is, for example, an aliphatic or aromatic ring system, such as 
Additional illustrative embodiments of R2 include nicotinoyl and its isomers, acryloyl, and substituents of the general formula Yxe2x80x2(CH2)nNH(CH2)nCHOH(CH2)nxe2x80x94 wherein Yxe2x80x2 is a generic substituent such as optionally substituted alkyl, piperazinyl, piperidinyl, cyclohexyl, phenyl or methoxy, and the like and wherein each n is independently an integer of 1-3. Yxe2x80x2 is quite variable and can generally include any noninterfering moiety. Additional embodiments include those of the general formula Yxe2x80x2NH(CH2)nxe2x80x94CO, wherein Yxe2x80x2 and n are as described above; also included are those of the general formula Yxe2x80x2(CH2)nNH(CH2)nCO where Yxe2x80x2 and n are as described above; and those of the formula Yxe2x80x2(CH2)nCO and Yxe2x80x2(CH2)nNHCO, wherein Yxe2x80x2 and n are as defined above; and those of the formula R2N(CH2)nxe2x80x94 wherein R is alkyl (1-6C) and n is an integer of 1-3.
With respect to R3:
Although R3 may be H, other embodiments are included and may be preferred. These include halo, OR, NR2, and alkyl (1-6C), as particularly desirable.
In embodiments wherein Z1 or Z2, preferably Z1, is CR4, where R4 is other than H, preferred embodiments of R4 include those of the formula R2N(CH2)nxe2x80x94 wherein each R is independently alkyl (1-6C) or H and n is an integer of 1-6; or of the formula Yxe2x80x2(xe2x80x94CH2)nxe2x80x94 wherein Yxe2x80x2 is as defined above and n is an integer of 1-6; or those of the formula Yxe2x80x2NHCO; or those of the formula R2NCO, wherein the R2 substituents taken together form a ring which may itself be substituted, preferably by alkyl arylalkyl, and the like. When R4 is Yxe2x80x2 (CH2)nxe2x80x94, for example, Yxe2x80x2 may be 
or R4 may be 
Additional illustrative embodiments of R4 include 2-, 3- and 4-pyridyl, 2-, 3- and 4-piperidyl.
The compounds of formulas (1)-(4) may be supplied in the form of their pharmaceutically acceptable acid-addition salts including salts of inorganic acids such as hydrochloric, sulfuric, hydrobromic, or phosphoric acid or salts of organic acids such as acetic, tartaric, succinic, benzoic, salicylic, and the like. If a carboxyl moiety is present, these compounds may also be supplied as a salt with a pharmaceutically acceptable base, including inorganic bases such as sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonium hydroxide and the like or a salt with a organic base such as caffeine.
Particularly preferred compounds of the invention are of formulas (5) and (6): 
In these compounds, R1 is of the formula shown, wherein each X3 is independently halo, alkyl (1-6C), OR or NR2, wherein R is H or alkyl (1-6C), and p is an integer of 0-3. R2, R3 and R4 are as defined above.
Also preferred are similar compounds where the positions of R3 and the illustrated embodiment of R1 are reversed; i.e., R3 is at position 5 and R1 is in position 6.
The compounds of the invention can be synthesized by a variety of methods most of them known in the art per se. The indole, benzimidazole, or benotriazole moiety may be supplied per se and the substituent R1 coupled thereto. R1 may be supplied as such, or its synthesis may be completed when the piperazyl or piperidyl residue is already coupled to the indole, benzimidazole or benotriazole moiety. Alternatively, especially in embodiments wherein R3 represents a non-hydrogen substituent, the appropriately substituted p-aminobenzoic acid derivative may be cyclized and then substituted with piperazine or piperidine.
Thus, for example, as shown in Reaction Scheme 1, a piperazine protected with tert-butyloxycarbonyl (BOC) is coupled to 5-carboxybenzimidazole (or 5-carboxy-indole, or 5-carboxy-benzotrazole) in a reaction mixture containing a coupling agent such as EDAC in an inert, aprotic solvent to obtain the coupled carboxamide which is then deprotected and treated with substituted or unsubstituted benzyl halides or benzoyl halides. 
Ra=for example, 2,6-difluorophenyl; 3,4-difluorophenyl; 2,3-difluorophenyl; 3,5-difluorophenyl, 3-chlorophenyl; 4-chlorophenyl; 4-carboxymethylphenyl; 4-methoxyphenyl; 4-trifluoromethyloxyphenyl; 4-methylphenyl; 6-chloropiperonyl; t-butylcarboxyphenyl; 3-trifluorophenyl; 2,4-dichlorophenyl; 3,4-dichlorophenyl; phenyl; methoxyphenyl; or p-toluyl.
Alternatively, as shown in Reaction Scheme 2, 5-carboxylated benzimidazole (or indole or benzotriazole) is reacted with a piperazine or piperidine moiety already substituted by X2xe2x80x94Ar. In this reaction, the piperazyl or piperidyl derivative is directly reacted with the carboxylated bicycloheteroatom-containing nucleus in the presence of a coupling agent such as EDAC in the presence of an inert solvent as set forth above. 
In order to form the substituted piperazine required for Scheme 2, piperazine is first converted to the BOC derivative and then reacted with ArCHO in the presence of a borohydride under acidic conditions to give the substituted piperazine as shown in Reaction Scheme 3. 
An alternative for coupling derivatized piperazine or piperidine to indole, benzimidazole or benzotriazole is shown in Reaction Scheme 4. In this reaction, the piperazine or piperidine ring is derivatized to a suitable leaving group as shown and then treated with a base such as NaH in an inert solvent to obtain the desired conjugate. 
Another alternative is shown in Reaction Scheme 5. In this approach, a protected piperidone is reacted in the presence of base, such as NaH, with the appropriate phosphonate ester to obtain a protected benzylene piperidine. The product is then deprotected and reacted with the carboxylate of indole, benzimidazole or benzotriazole using an appropriate dehydrating agent. The product is then reduced to the desired arylalkylated piperidine derivative. 
Reaction Scheme 6 illustrates a method for preparing compounds of the invention in which the indole is substituted in the 6-membered ring thereof. In Reaction Scheme 6, the appropriately substituted aniline is reacted with 1-methylmercaptyl-2,2-dialkoxyethane in the presence of tertiary butyryl chloride and base to provide the desired indole. Depending on the nature of the substitution of the aniline starting material, more than one isomer may result as shown. The methylmercaptyl group remaining on the 5-membered ring is reduced with Raney nickel and a mandatory methyl group included on the original aniline moiety is hydrolyzed to the corresponding carboxylic acid. The resulting acid is then reacted with the desired piperidine or piperazine derivative in the presence of a coupling agent such as EDC. 
Alkylation of the nitrogens on the indole, benzimidazole or benzotriazole nucleus in the compounds per se is carried out by conventional means by reacting the halide of the substituent to be added in the presence of base and acetone, as shown in the illustrative alternative depictions of Scheme 7. 
where X=H, OMe, Cl;
each R is H or alkyl;
n is an integer; or 
xe2x80x83where X=H, OHC3, Cl, CH3, etc.;
each R is H, alkyl, aryl
or together both R form 
Substituents at the 3-position of indole can be modified using the general procedures shown in Scheme 8: 
where X=OMe, Cl, CH3;
each R is H, alkyl, aryl or together the R groups are piperazinyl, 4-benzylpiperazinyl, etc.
Alternatively, Scheme 9 can be used: 
For synthesis of compounds wherein n is Ixe2x80x94i.e., wherein the piperidine ring contains one additional substituent other than those mandated in the compounds of the invention, the 4-substituted piperidine is first protected using BOC2O in THF or other aprotic solvent and then reacted with, for example, an alkyl iodide in the presence of S-butyl lithium/TMEDA using, for example, ether as a solvent to produce the alkylated piperidine. The alkylated piperidine is then converted to the invention compound by deprotection followed by formation of the carboxamido linkage to the indoyl residue. This is exemplified below.
For compounds of the invention that are indoles substituted at the 3-position, the Reaction Scheme shown at the beginning of Example 23 may conveniently be used. Typically, the carboxamide starting material is treated with trifluoroacetic anhydride to obtain the trifluoroacetyl intermediate, which is also a compound of the invention. Upon treatment with base, the 3-carboxylic acid is formed which can then be reacted with a suitable amine to obtain additional compounds of the invention.
The compounds of the invention are useful in treating conditions associated with inflammation. Thus, the compounds of formulas (1)-(4) or their pharmaceutically acceptable salts are used in the manufacture of a medicament for prophylactic or therapeutic treatment of mammals, including humans, in respect of conditions characterized by excessive production of cytokines and/or inappropriate or unregulated cytokine activity on such cells as cardiomyocytes, cardiofibroblasts and macrophages.
The compounds of the invention inhibit the production of cytokines such as TNF, IL-1, IL-6 and IL-8, cytokines that are important proinflammatory constituents in many different disease states and syndromes. Thus, inhibition of these cytokines has benefit in controlling and mitigating many diseases. The compounds of the invention are shown herein to inhibit a member of the MAP kinase family variously called p38 MAPK (or p38), CSBP, or SAPK-2. The activation of this protein has been shown to regulate the production of prostanoids, such as PGE2, and matrix metalloproteinases, such as collagenase-3, and to accompany exacerbation of the diseases in response to stress caused, for example, by treatment with lipopolysaccharides or cytokines such as TNF and IL-1. Inhibition of p38 activity, therefore, is predictive of the ability of a medicament to provide a beneficial effect in treating diseases such as coronary artery disease, congestive heart failure, cardiomyopathy, myocarditis, vasculitis, restenosis, such as occurs following coronary angioplasty, atherosclerosis, rheumatoid arthritis, rheumatoid spondylitis, osteoarthritis, gouty arthritis and other arthritic conditions, multiple sclerosis, acute respiratory distress syndrome (ARDS), asthma, chronic obstructive pulmonary disease (COPD), silicosis, pulmonary sarcosis, sepsis, septic shock, endotoxic shock, toxic shock syndrome, heart and brain failure (stroke) that are characterized by ischemia and reperfusion injury, surgical procedures, such as transplantation procedures and graft rejections, cardiopulmonary bypass, coronary artery bypass graft, CNS injuries, including open and closed head trauma, inflammatory eye conditions such as conjunctivitis and uveitis, acute renal failure, glomerulonephritis, inflammatory bowel diseases, such as Crohn""s disease or ulcerative colitis, graft vs. host disease, bone resorption diseases like osteoporosis, type II diabetes, pyresis, psoriasis, cachexia, viral diseases such as those caused by HIV, CMV, and Herpes, and cerebral malaria, tumor metastases and acute pain, such as that accompanying dental surgery, dysmenorrhea and post-orthopedic surgery.
Within the last several years, p38 has been shown to comprise a group of MAP kinases designated p38xcex1, p38xcex2, p38xcex3 and p38xcex4. Jiang, Y. et al. J Biol Chem (1996) 271:17920-17926 first reported characterization of p38xcex2 as a 372-amino acid protein closely related to p38xcex1. Kumar, S. et al. Biochem Biophys Res Comm (1997) 235:533-538 and Stein, B. et al. J Biol Chem (1997) 272:19509-19517 reported a second isoform of p38xcex2, p38xcex22, containing 364 amino acids with 73% identity to p38xcex1. All of these reports show evidence that p38xcex2 is activated by proinflammatory cytokines and environmental stress, although the second reported p38xcex2 isoform, p38xcex22, appears to be preferentially expressed in the CNS, heart and skeletal muscle compared to the more ubiquitous, tissue expression of p38xcex1. Furthermore, activated transcription factor-2 (ATF-2) was observed to be a better substrate for p38xcex22 than for p38xcex1, thus suggesting that separate mechanisms of action may be associated with these forms. The physiological role of p38xcex21 has been called into question by the latter two reports since it cannot be found in human tissue and does not exhibit appreciable kinase activity with the substrates of p38xcex1.
The identification of p38xcex3 was reported by Li, Z. et al. Biochem Biophys Res Comm (1996) 228:334-340 and of p38xcex4 by Wang, X., et al., J Biol Chem (1997) 272:23668-23674 and by Kumar, S., et al., Biochem Biophys Res Comm (1997) 235:533-538. The data suggest that these two p38 isoforms (xcex3 and xcex4) represent a unique subset of the MAPK family based on their tissue expression patterns, substrate utilization, response to direct and indirect stimuli, and susceptibility to kinase inhibitors.
Various results with regard to response to drugs targeting the p38 family as between p38xcex1 and either the putative p38xcex21 or p38xcex22 or both were reported by Jiang, Kumar, and Stein cited above as well as by Eyers, P. A. et al. Chem and Biol (1995) 5:321-328. An additional paper by Wang, Y. et al. J Biol Chem (1998) 273:2161-2168 suggests the significance of such differential effects. As pointed out by Wang, a number of stimuli, such as myocardial infarction, hypertension, valvular diseases, viral myocarditis, and dilated cardiomyopathy lead to an increase in cardiac workload and elevated mechanical stress on cardiomyocytes. These are said to lead to an adaptive hypertrophic response which, if not controlled, has decidedly negative consequences. Wang cites previous studies which have shown that in ischemia reperfusion treated hearts, p38 MAPK activities are elevated in association with hypertrophy and programmed cell death. Wang shows in the cited paper that activation of p38xcex2 activity results in hypertrophy, whereas activation of p38xcex1 activity leads to myocyte apoptosis. Thus, selective inhibition of p38xcex1 activity as compared to p38xcex2 activity will be of benefit in treating conditions associated with cardiac failure. These conditions include congestive heart failure, cardiomyopathy, myocarditis, vasculitis, vascular restenosis, valvular disease, conditions associated with cardiopulmonary bypass, coronary artery bypass, grafts and vascular grafts. Further, to the extent that the xcex1-isoform is toxic in other muscle cell types, xcex1-selective inhibitors would be useful for conditions associated with cachexia attributed to TNF or other conditions such as cancer, infection, or autoimmune disease.
The compounds described herein which selectively inhibit the activity of the p38xcex1 isoform are useful for treating conditions associated with activation of p38xcex1, in particular those associated with cardiac hypertrophy, ischemia or other environmental stress such as oxidation injury, hyperosmolarity or other agents or factors that activate p38xcex1 kinase, or cardiac failure, for example, congestive heart failure, cardiomyopathy and myocarditis.
Compounds which exhibit this activity are of the formula 
wherein R1, R2, R3, Z1, and Z2 are as defined in claim 1.
The manner of administration and formulation of the compounds described herein will depend on the nature of the condition, the severity of the condition, the particular subject to be treated, and the judgement of the practitioner; formulation will depend on mode of administration. As these compounds are small molecules, they are conveniently administered by oral administration by compounding them with suitable pharmaceutical excipients so as to provide tablets, capsules, syrups, and the like. Suitable formulations for oral administration may also include minor components such as buffers, flavoring agents and the like. Typically, the amount of active ingredient in the formulations will be in the range of 5%-95% of the total formulation, but wide variation is permitted depending on the carrier. Suitable carriers include sucrose, pectin, magnesium stearate, lactose, peanut oil, olive oil, water, and the like.
The compounds useful in the invention may also be administered through suppositories or other transmucosal vehicles. Typically, such formulations will include excipients that facilitate the passage of the compound through the mucosa such as pharmaceutically acceptable detergents.
The compounds may also be administered topically, for topical conditions such as psoriasis, or in formulation intended to penetrate the skin. These include lotions, creams, ointments and the like which can be formulated by known methods.
The compounds may also be administered by injection, including intravenous, intramuscular, subcutaneous or intraperitoneal injection. Typical formulations for such use are liquid formulations in isotonic vehicles such as Hank""s solution or Ringer""s solution.
Alternative formulations include nasal sprays, liposomal formulations, slow-release formulations, and the like, as are known in the art.
Any suitable formulation may be used. A compendium of art-known formulations is found in Remington""s Pharmaceutical Sciences, latest edition, Mack Publishing Company, Easton, Pa. Reference to this manual is routine in the art.
The dosages of the compounds of the invention will depend on a number of factors which will vary from patient to patient. However, it is believed that generally, the daily oral dosage will utilize 0.001-100 mg/kg total body weight, preferably from 0.01-25 50 mg/kg and more preferably about 0.01 mg/kg-10 mg/kg. The dose regimen will vary, however, depending on the conditions being treated and the judgment of the practitioner.
As implicated above, although the compounds of the invention may be used in humans, they are also available for veterinary use in treating animal subjects.